Connection between space frame roof and walls in Haiti building

[libby87]

I am working on a classroom structure in Haiti. The walls are constructed of compressed stabilized earth blocks with rebar. The top course consists of a U-shaped block "ring beam" filled with reinforced concrete. The roof structure is a space frame made out of welded steel pipe or tubes, connected with crude node pieces which we're still working out how to fabricate down there.

I am trying to think of the best way to connect the roof to the wall, through the concrete in the ring beam, in a way that distributes the load along the wall as evenly as possible and helps the roof function as a flexible diaphragm to transfer lateral loads. Resources are limited and we cannot just order any steel section we like, but must work with the simplest configurations possible. Any ideas would be appreciated, or if anyone would like to chat about the trials I'm encountering with the space frame fabrication that would be great too. I have no previous experience designing in developing countries with no codes and limited material choices, and very few precedents to work from. Thanks!

 

[dhengr]

Libby87:

Without more info. in the way of wall thickness and height, block size, reinf’g. locations, mechanical properties of the wall system, etc.; and more info. on the space frame, size, bearing points, etc.; your discussion may not go much further than this. Some sketches might be in order. But, since you have a ring beam (bond beam) at the top of the wall, why not core down into the wall a couple feet, place A.B’s. and fill the rough cored holes while filling the bond beam with conc.

Sounds like an interesting project and a real opportunity to do some good where it is truly needed. With your experience, follow the logic and intent of the codes, that we use to do our designs here, the best their methods will allow. Almost anything you do will be better than what they have, and it would be unlikely that you can fully comply with our codes, given what they have to work with.

Where is Concretemasonry when we need him? Dick, check in here and add your $.02 worth.

 

[MintJulep]

You will likely get better answers if you ask in forum507 or one of the other building fora.

I suggest that you need to think about keeping the roof attached during hurricanes too.